Biology topic 4

• What is secreased by bacteria that make us feel ill ?

  Toxins
• Pharmaceutical companies make medicine from plants
• Pharmaceutical companies also produce synthetic drugs
• Willow bark contains salicin
• Salicylic acid, found in willow bark, has antibacterial properties, which is why it is used in making aspirin
• Aspirin helps in preventing blood clots
• Foxglove contains digitoxins used in the heart drug called digitalis
• Characteristics of good medicine:

  • Effective: prevents and cures infections
  • Safe: not toxic
  • Stable: can be used under normal conditions
  • Successfully taken into and removed from the body: reaches its target and is cleaned out of the system
• Drug development testing involves 5 steps and 3 phases:

  Steps:

  1. Decide which diseases to treat

  2. Decide which traditional remedies to use

  3. Decide to use synthetic chemicals

  4. Complete initial tests in laboratories

  5. Test the drug on animal tissues

  Phases:

  1. Testing on healthy volunteers to determine dosage range, potential side effects, and safety profile

  2. Testing on patients to provide evidence of effectiveness on specific conditions

  3. Testing on a larger population to gather comprehensive data on safety and efficiency, also involves licensing
• Double-blind tests: neither the patients nor doctors know the drug being used
• Placebo: a tablet, drug, or injection that does not contain the actual drug